If the computer has had windows reinstalled, and by default, came with ie7, it will not revert back to IE6 when uninstalled, but you can download ie6 from here: http://www.filehippo.com/download_internet_explorer/317/
Whether or not Windows will accept it, I don't know. If you must it is always possible to reinstall IE7 again or get Firefox with an IE6 theme if the look of IE6 is what you want.
If I remove IE 7 from programs will it revert back to IE 6? I just had Windows reinstalled by someone and not sure if that would work?